<!--
 * Tencent is pleased to support the open source community by making BK-JOB蓝鲸智云作业平台 available.
 *
 * Copyright (C) 2021 THL A29 Limited, a Tencent company.  All rights reserved.
 *
 * BK-JOB蓝鲸智云作业平台 is licensed under the MIT License.
 *
 * License for BK-JOB蓝鲸智云作业平台:
 *
 *
 * Terms of the MIT License:
 * ---------------------------------------------------
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and
 * to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of
 * the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
 * THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
-->

<template>
  <icon
    v-if="showBack"
    class="jb-router-back"
    svg
    type="back1"
    @click="handleGoBack" />
</template>
<script>
  import _ from 'lodash';

  import {
    taskExport,
    taskImport,
  } from '@utils/cache-helper';

  export default {
    name: 'RouterBack',
    props: {
      /**
       * @desc 通过浏览器直接访问时总是显示路由回退按钮，通过iframe访问系统时需要根据场景显示路由回退按钮。
       */
      mode: {
        type: String,
        default: 'window',
      },
    },
    data() {
      return {
        showBack: false,
      };
    },
    watch: {
      '$route'() {
        this.check();
        const { name } = this.$route;
        // 路由变更清空作业导入缓存
        if (name !== 'taskImport') {
          taskImport.clearItem();
        }
        // 路由变更清空作业导入数据
        if (name !== 'taskExport') {
          taskExport.clearItem();
        }
      },
    },
    created() {
      this.timer = '';
      this.$once('hook:beforeDestroy', () => {
        clearTimeout(this.timer);
      });
    },
    mounted() {
      this.check();
    },
    methods: {
      check() {
        // iframe 嵌入的方式有两种场景
        // 1，paas 桌面的方式需要显示完整的导航
        // 2，第三方系统嵌入的方式不需要显示
        if (window.frames.length !== parent.frames.length
          && this.mode !== 'window') {
          // iframe 访问路由需要做定制处理
          this.showBack = false;
          // 在作业执行详情页面访问步骤执行详情页，显示路由回退按钮
          if (this.$route.name === 'historyStep'
            && this.$route.query.from === 'historyTask') {
            this.showBack = true;
          }
          return;
        }
        this.timer = setTimeout(() => {
          try {
            const viewInstance = _.last(this.$route.matched).instances.default || {};
            this.showBack = Object.prototype.hasOwnProperty.call(viewInstance, 'routerBack');
          } catch (error) {
            this.check();
          }
        }, 100);
      },
      handleGoBack() {
        window.routerFlashBack = true;
        const viewInstance = _.last(this.$route.matched).instances.default || {};
        if (typeof viewInstance.routerBack === 'function') {
          viewInstance.routerBack();
        }
      },
    },
  };
</script>
<style lang='postcss' scoped>
  .jb-router-back {
    position: relative;
    z-index: 1999;
    flex: 0 0 auto;
    padding: 16px 8px 16px 24px;
    margin-left: -24px;
    font-size: 14px;
    color: #3a84ff;
    cursor: pointer;
  }
</style>
